Beat it and really enjoyed it. It took a few tries but I feel like I figured out "the system" eventually after which it became quite easy. The pirates never seem to become much of a threat, and placing an archery tower as soon as they turn up is usually enough to deter them succesfully.
It would be nice if there was a way to see how many of each building you have - the lumber and mining shacks are not always easy to see and it's useful to know how many you have generating income for you.
EDIT: Beat it multiple times, lowest was around 85 people and highest 110+, but it could be higher I suppose - there is a point after which you could conceivably expand infinitely.